It is known that it is desirable to be able to wind up electrical leads when they are not in use. A problem with reeling devices for electrical leads is that an electrical connection must be made to a lead on a rotating spool. The prior art solutions to this problem fall into two categories. In one category are devices which employ two coils of different diameters arranged such that as a lead is drawn from the large coil, the turns of the smaller coil can separate, e.g. U.S. Pat. No. 4,989,805. The other category comprises devices that use slip rings to make electrical connections to a lead on a spool, e.g. U.S. Pat. No. 5,339,461.
Devices in the first category have not established themselves in the marketplace and it is believed that this is because they have proved unreliable. Devices in the second category are unsuitable for small signal applications, for example microphone or headphone leads, because of noise caused by the slip ring contacts.